/* Copyright (c) 2007, Sun Microsystems, Inc.
All rights reserved.

Redistribution and use in source and binary forms, with or without 
modification, are permitted provided that the following conditions are met:

 * Redistributions of source code must retain the above copyright notice, 
   this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright 
   notice, this list of conditions and the following disclaimer in 
   the documentation and/or other materials provided with the distribution.
 * Neither the name of Sun Microsystems, Inc. nor the names of its 
   contributors may be used to endorse or promote products derived 
   from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 
TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */     

package ztpviewer;

import org.jdesktop.application.Application;
import org.jdesktop.application.Task;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.Iterator;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.event.IIOReadProgressListener;
import javax.imageio.stream.ImageInputStream;

public class LoadImageTask extends Task<BufferedImage, Void> {
    private static Logger logger = Logger.getLogger(LoadImageTask.class.getName());
    private final URL url;
    private ImageReader imageReader = null;

    public LoadImageTask(Application app, URL url) {
	super(app, "LoadImageTask"); 
	this.url = url;
    }

    protected final URL getImageURL() { 
	return url;
    }

    @Override protected BufferedImage doInBackground() {
	IIOReadProgressListener rpl = new IIOReadProgressAdapter() {
	    public void imageProgress(ImageReader r, float p) {
		setProgress(p, 0.0f, 100.0f);
	    }
	};
	message("startedLoadingImage", url);
	imageReader = findImageReader(url);
	return loadImage(imageReader, rpl);
    }

    private void completionMessage(String resourceKey) {
	message(resourceKey, url, getExecutionDuration(TimeUnit.MILLISECONDS));
    }

    @Override protected void cancelled() {
        if (imageReader != null) {
            imageReader.abort();
        }
	completionMessage("cancelledLoadingImage");
    }

    @Override protected void interrupted(InterruptedException e) {
        if (imageReader != null) {
            imageReader.abort();
        }
	completionMessage("cancelledLoadingImage");
    }

    @Override protected void succeeded(BufferedImage image) {
	completionMessage("finishedLoadingImage");
    }

    @Override protected void failed(Throwable e) {
	completionMessage("failedLoadingImage");
    }
    
    @Override protected void finished() {
	imageReader = null;
    }
    

    /* The methods below are what's required by the Java imaging
     * API to enable tracking the progress of an ImageIO read()
     * and optionally aborting it.  If we weren't interested in
     * tracking image-loading progress or supporting Task.cancel()
     * it would be enough to just use ImageIO.read().
     */
    private ImageReader findImageReader(URL url) {
	ImageInputStream input = null; 
	try {
	    input = ImageIO.createImageInputStream(url.openStream());
	}
	catch(IOException e) {
	    logger.log(Level.WARNING, "zly adres URL obrazka " + url, e);
	}
	ImageReader reader = null;
	if (input != null) {
	    Iterator readers = ImageIO.getImageReaders(input);
	    while((reader == null) && (readers != null) && readers.hasNext()) {
		reader = (ImageReader)readers.next();
	    }
	    reader.setInput(input);
	}
	return reader;
    }

    private BufferedImage loadImage(ImageReader reader, IIOReadProgressListener listener) {
	BufferedImage image = null;
	try {
	    if (listener != null) {
		reader.addIIOReadProgressListener(listener);
	    }
	    int index = reader.getMinIndex();
	    image = reader.read(index);
	}
	catch (IOException e) { 
	    logger.log(Level.WARNING, "Ladowanie obrazka sie nie powiodlo", e);
	}
	finally {
	    ImageInputStream input = (ImageInputStream)(reader.getInput());
	    if (input != null) {
		try { input.close(); } catch (IOException e) { }
	    }
	    if (reader != null) {
		reader.removeAllIIOReadProgressListeners();
		reader.dispose();
	    }
	}
	return image;
    }

    /* Makes creating an IIOReadProgressListener less horrible looking; see 
     * LoadImageTask.doInBackground() above.
     */
    private static class IIOReadProgressAdapter implements IIOReadProgressListener {
	public void imageStarted(ImageReader rdr, int imageIndex) { }
	public void imageProgress(ImageReader rdr, float percentageDone) { }
	public void imageComplete(ImageReader rdr) { }
	public void readAborted(ImageReader rdr) { }
	public void sequenceStarted(ImageReader rdr, int minIndex) { }
	public void sequenceComplete(ImageReader rdr) { }
	public void thumbnailStarted(ImageReader rdr, int imageIndex, int thumbIndex) {	}
	public void thumbnailProgress(ImageReader rdr, float percentageDone) { }
	public void thumbnailComplete(ImageReader rdr) { }
    }
}

